Apparatus for making concrete slabs.



C. R BURKHARDT.

APPARATUS FOR MAKING CONCRETE SLABS.

APPLICATION FILED JUNE 3.19I6

1,291,637., Patented Jan. 14, 1919.

35 4 SHEETS-SHEET l H- I 1 I i 5 7 mgi KWM C. R BURKHARDT.

APPARATUS FOR MAKING CONCRETE SLABS.

APPLICATION FILED IUNE 3| I9I6 OJ 1 OJ l 2 )T A: H 1 H 9 m a h m a o E 2m F o P IQ 0 3 3 a J 0 W m 7 W 5 W h I n a I- p mm ||Ir DE. 3 5 5 "N 0 ww w 0 w w 6 p. I I I 6 i H 7 J 3 Q 5 .5 ,1 4, 6 0 0 0 0 0 a 3 V I 4 A,A, E A, 4 w W O I I n L H q H 1 9 M H I II II II I 2 WT I I II- w Ii 9 vI I 1 W w W W M fl o z C. R BURKHARDT.

APPARATUS FOR MAKING CONCRETE SLABS.

APPLICATION FILED JUNE 3. I9I6 Patented Jan. 14, 1919.

4 SHEETS-SHEET 3.

c. R BURKHARDT.

APPARATUS FOR MAKING CONCRETE SLABS.

APPLICATION FILED JUNE 3 1916 1,291,637. v Patented Jdn. 14,1919

4 SHEETS-SHEET 4.

6 p I 41 r UNITED STATES PATENT OFFICE.

CURT R. BTTRKHARDT, F TEANECK, NEW JERSEY, ASSIGNOR OF ONE-HALF TO JOHNA.

SCHARWATH. 0F ELIZABETH, NEW JERSEY.

APPARATUS FOR MAKING CONCRETE SLABS.

Specification of Letters Patent.

Patented Jan. 14, 1919.

Application filed June 3, 1916. Serial No. 101,461.

To all whom it may concern Be it known that I, CURT R. BURKHARDT, asubject of the Emperor of Germany, (who will become a citizen of theUnited States on June 8, 1916,) and a resident of Teaneck,

. Bergen county, and State of New Jersey,

have invented certain new and useful Improvements in Apparatus forMaking Concrete Slabs, of which the following is a specification,reference being had to the accompanying drawings, forming a partthereof.

My invention relates to apparatus for producing plates, slabs, tiles,shingles or like articles from hydraulic cement. sand and asbestosfiber. or from some other suitable concrete mixture. It has specialreference to machines for manufacturing concrete shingles by theapplication of high pressure and heat.

One object of my invention is to provide a machine of the aforesaidcharacter that shall be compact in construction, reliable in operation,and adapted for producing a plurality of shingles or other units at onetime.

Another object is to provide a press having a stationary head, a plungeror piston, and a plurality of intermediate press heads adapted to besupported in spaced relation at fixed distances apart when the plungeris released and to be forced together when the plunger is actuated.

Still another object is to provide more than one set of molds and aplurality of mold racks on opposite sides of the press, whereby they areadapted to support one set of molds in position to be loaded while theother set is being subjected to the action of the press.

Another object is to heat the press members for the purpose ofpreventing the concrete from adhering thereto as the shingles or thelike are made in the machine, without interfering with the operation ofthe movable press members.

Other objects and advantages of my invention will be set forthhereinafter and in order that my invention may be thoroughly understoodI will now proceed to describe the same in the following specificationand then point out the novel features thereof in appended claims.

Referring to the drawings:

Figure 1 is a sectional elevation of a press arranged and constructed inaccordance with and constituting an embodiment of my invention. Certainof the molds are shown in elevation and others in section, some beingfilled and others empty, in order to clearly bring out the structure andoperation of the press.

Fig. 2 is a sectional elevation at right angles to Fig. 1.

A plan View of the same machine is shown in Fig. 3; and

Fig. 4 is a sectional plan view, taken on the line 41 of Fig. 1. ,7

One of the transverse bars which support a releasing stud, is shown on alarger scale in Fig. 5.

Fig. 6 is a front elevation of the upper part of the machine andillustrates the steam connections between the press heads.

Fig. 7 is a sectional plan view of the stationary press head located atthe top of the machine.

Fig. 8 is a similar view of one of the intermediate press heads.

Fig. 9 is a sectional plan view of the press head which is attached tothe plunger of the press; and

Fi 10 is a bottom plan view of the same mem er.

Fig. 11 is a plan view showing one of the guide bars which are attachedto the intermediate or floating press heads.

Figs. 12 and 13 are sectional details taken on the lines 1212 and 13-13of Fig. 2.

The embodiment of my invention which is illustrated in the drawingscomprises a base 15, a plunger 25, a stationary press head 30 at thetop, a plurality of intermediate press heads 40, two sets of molds 50. amold support 60, and two sets of supporting racks.

The base.

The base 15 has a bottom flange 16 by which it may be bolted orotherwise secured to the floor or foundation indicated at 17. It isfurthermore, provided with a cylindrical recess 18 which is adapted toreceive the cylindrical plunger 25 and is enlarged into a chamber 19 atthe bottom. The recess 18 Q hashes? constitutes a hydraulic cylinder, afluid supply pipe being connected to the chamber l9 as clearly shown inFig. 2. A drainage plpe 21 is connected through a port or passage 22 toan annular groove 23 at the mouth of the cylindrical opening 18.

The plunger 25 has a flange plate.26 attached to it by bolts 27 and isprovided wlth a recess 28 which is adapted to contain cooling fluid. Theflange plate is arranged to limit the downward movement of the plunger.

Stationary press head.

The press head 30 has the general form shown in the sectional plan ofFig. 7 and is securely held in position by a plurality of massive tiebolts or studs 31 which extend through recessed lugs 32 of the base 15at their lower ends, and through holes 33 in the press head 30 at thetop, the press head being securely clamped against collars orenlargements 34 of the bolts by means of cap nuts 35.

The press head 30 is further provided with recesses 36 constitutingsteam chambers which are interconnected by a port 37 and respectivelycommunicate with admission and exhaust passages 38 and 39.

Intermediate press heads.

Each of the intermediate press heads 40 has the general form shown inFig. 8, being provided with curved corner notches 41 to cooperate withthe studs or tie bolts 31 which guide the head as it is moved up anddown during the operation of the press. Each press head has recesses 36,a port 37, inlet and exhaust passages 38 and 39 corresponding to thestationary press head, and a pair of spaced holes 42 to receive acylindrical projection 61 of the mold support 60. Furthermore, eachpress head, including the stationary press head 30, has a transverseslot or groove 43 in which a wedge-bar 44 is slidably mounted, the barbeing held in position by a bottom plate 45 which is secured to the bodyof the press head, and forms a part of it. The relation of'these shownin Figs. 1 and 2.

The slots 43 extend transversely through the cylindrical projections 61of the mold parts is clearly supports which are provided with slots 62to The adjustment of the bars is effected by screws 48 which extendthrough suitable holes in brackets 49 and engage tapped holes in theouter ends of the bars 44. The brackets 49 are attached to the pressheads 40 by bolts or other suitable means as indicated in Fig. 12.

The mold supports 60 for the stationary press head 30 are similar tothose employed with the intermediate press heads except that thecylindrical projections are made longer on account of the thickness ofthe stationary press head. These projections are designated 61*. Each ofthe press heads 40 is formed on the top to cooperate with the bottomplate of the mold as hereinafter explained.

Mold.

, shape of the shingle or tile.

Each mold has an upwardly-extending projection or lug 55 and anoutwardly-extending handle 56 on the same side. The lug is so placedthat when the mold is moved into position in the press, the lug acts asa stop and engages the side of the press head, as shown in Fig. 1. Thehandle is adapted to be utilized for moving the mold into and out of thepress.

The mold is provided with lateral projections or tongues 57 which engagegrooves 64 in the supports and are guided thereby when it is in positionin the press.

Supporting males.

The above-described parts constitute an operative machineand one set ofmolds may .be filled outside of the press while the other set is in thepress. However, I prefer to pro vide racks in which the molds areadapted to be supported for filling when they are not between the pressheads. The racks comprise fourframes 70 which are secured near theirrespective ends to the base 15, and the stationary press head 30. Eachof the frames has an inwardly-extending flange or projection 71 which isnotched to constitute steps 72 and is engaged, as clearly shown in Fig.6 by press head fingers or lugs 73. r

The lowest intermediate press head 40 rests upon'the bottom step 72 whenthe plunger 25 is released, and each successive press head above itrests upon the successive upper steps.

The arrangement of parts is such that when the plunger 25 is actuated,by admitting hydraulic or other fluid pressure to the chamber 19 forexample, the press heads are successively raised until they are allcarried by the plunger and are finally subjected to high compressionbetween the stationary press head 30 and the plunger. 7

A press head 85 which is shown in sectional plan in Fig. 9 and in bottomplan in Fig. 10, is secured to the flange plate 26 of the plunger. Ithas an upwardly-extending body having recesses 36 connected by a port37, inlet and outlet passages 38 and 39 corresponding to the press heads40 and the stationary press head 30.

Each of the press heads 10 and the press head 85 are formed to extendinto the opening in the bottom of the mold above it so that the bottomplate 52 is forced upwardly and compresses the concrete mixture, withwhich the mold is filled, between the mold plate 53 and the bottom plate45 of the head above.

The racks are further provided with stationary ide bars 74 having slotsor grooves 75 constituting guideways to cotiperate with the tongues 57of the molds. The bars 74 are arranged in pairs and the frames 70 haveflanges 76 which close the outer ends of the grooves 75 and constitutestops to imit the outward movement of the molds. As clearly shown inFig. 1, when the molds are pulled outwardly by the handles 56 intoposition to be filled, the outer ends of the tongues 57 engage theflange 76, there is therefore no danger of accidentally pullin the moldout too far.

The bars 75 have downwardly-extending T-shaped projections 77 which areadapted to support transverse bars 78 having end notches 79 to provideforks as clearly shown in Fig. 5. Near the center of each bar 78 is atapped hole through which extends a screw-threaded stud 81. The locationof the T-shaped projections 77 and of the bars 78 are such that thestuds 81 are almostdirectly under the centers of the removable bottomplates 52 of the molds. At least they are in position to exert an upwardpressure upon the mold plate when the mold has been pulllied out of thebody of the press onto the rac Plunger press head.

As clearly shown in Fig. 10, the press head 85 which is attached to theflange plate 25 of the plunger, has diagonal slots 86 on its bottom.surface, these slots being in communication with the chamber or recesses28 of the plunger as indicated in Fig. 1. They are for the purpose ofintroducing cooling fluid such as air or water to the plunger.

The outlet port 39 of the stationary press head 30 is connected to theinlet port 38 of the press head 40, directly below it, by means of theflexible elbowsteam pipe connection 90. The outlet 39 of this press headis similarly connected to the inlet passage of the press head belowandso on, each of the press heads being in this way interconnected, theoutlet port 39 of the press head 85 which is secured to the plungerbeing connected to a suitable exhaust pipe 91.

The arrangement of pipe connections is such as not to interfere with theoperation ofthe press which will now be discussed.

Operation.

Assuming that the parts occupy substantially the positions shown inFigs. 1 and 2, and that the molds 50, which are carried by the presshead supports, are filled with concrete mixture from which the slabs 0rshingles are to be made, a suitable wrench or key is first employed forturning the studs 48 so as to draw the wedge bars 44 to the right asshown in Fig. 2. The wedge surfaces 46 of the bars coiiperate with thewedge blocks 47 and lift the supports 60 and the molds 50 which arecarried thereby. Thus the concrete material in the molds is held inplace under slight compression between the bottom plates 45 and the moldplates 53.

If hydraulic pressure is admitted through pipe 20, to the chamber 19 andthe plunger forced upwardly, the face of the press head will firstengage the bottom plate 52 of the lowest mold 50 and will lift the presshead 40 above, the concrete material in the mold being compressedsomewhat by the weight of the press head which rests upon it.

Each successive mold and press head is raised until the entire seriesare borne by the plunger. The continued upward movement of the plungervery highly compresses the material in the several molds between thepress head 85 and the stationary press head 30. The press head 85 has anedge notch forming a shoulder 87 which lifts the mold if the press isactuated when the mold is empty and may limit the relative movementbet-ween the press head and the mold so as to definitely determine thethickness of the product when the molds are filled, al-

though I prefer to depend upon a measured quantity of material andpredetermined pressure.

While the shingles or slabs are being subjected to very high pressure inthehydraulic press, the steam or other suitable heating fluid isadmitted through a valve 92 and inlet opening 38 into chambers 36 of thestationary press head 30. The steam flows from this point through theheating chambers 36 of the several press heads and is finally dischargedthrough the exhaust pipe 91. Thus the press heads are all heated to apredetermined temperature and the slabs ortiles are subjected to hightemperature as well as high pressure. Such pressures and temperaturesare employed as to rapidly desired length of time but'with hightemperatures and pressures a very short time is suflicient. When thetiles are complete and the fluid pressure in the chamber 19 is relieved,the plunger 25 falls to its original position and the several molds aresupported by the steps 72 of the frame where they are in position to betransferred from the supports 60 to the guide bars 74, the grooves 64 ofthe supports 60 being in alinement with the slots 75 of the guide barsas indicated in Fig. 1.

The molds are next pulled outwardly into the racks, and a key or asocket wrench is employed for turning the studs 81 to push the completedshingles or tiles upwardly out of the molds.

As soon as the molds containing the completed product are pulled out ofthe press into the racks, the other set of molds, which have been in theracks in position for filling,

are immediately pushed into the press so that the press may again beactuated and the new set of shingles or tiles subjected to high pressureand heat while the set first completed are being removed from the moldsand the molds again filled.

One set of molds on one side of the press may all be filled at one timewhile the molds on the other side are in the press, and vice versa, butI believe it is preferable to introduce successive molds alternatelyfrom the opposite sides, since by this means there are empty molds oneach side of the press which are well spaced apart, and are in positionto be filled with ease. For example, a man may be stationed on each sideof the press for filling the molds and removing the completed ones.

The number of molds and press heads may obviously be increasedindefinitely, the number employed being determined by the desiredcapacity of the machine, and the number of men which can economically beemployed on the machine at one time, etc.

It is obvious that I depend upon the force of gravity for-returning themolds and press heads to their initial positions and .while ll believethis is preferable, the press may obviously be rearranged to operate inother planes and in fact, it may be inverted provided springs or othersuitable means are arranged to return the members to their initialpositions after each operation.

meme? The structure may be modified in various ways within the spiritand scope of my invention, and T intend that only such limitaholdersadapted to be inserted in the compression spaces, and means for clampingthe mold holders to .close the molds and lock themin place before thepress is actuated.

2. A press comprising a pair of spaced press heads, means for actuatingthe press to move the heads one toward the other, an interposed floatingpress head arranged to provide a plurality of compression spaces, moldsfor the press, and means for closing each mold and pressing it againstthe adjacent press head before the working pressure is applied.

3. A press comprising a pair of spaced press heads, means for actuatingthe press to move the heads one toward the other, an interposed floatingpress head arranged to provide a plurality of compression spaces,interposed molds in the spaces between press heads, mold holders forsuspending each mold from the press head above, and means for clampingthe mold in position independently of the press actuating means.

4. A press comprising a pair of spaced press heads, means for actuatingthe press to move the heads one toward the other, an interposed floatingpress head arranged to provide a plurality of compression spaces,interposed molds in the spaces between press heads, mold holders forsuspending each mold from the press head above, and transverse bars forlocking the molds and holding i them closed.

5. A press comprising a pair of spaced no press heads tending toseparate, and adapted to be moved one toward the other, and aninterposed floating press head adapted to provide a plurality ofcompression spaces, means for adjustably suspending molds 11s from theadjacent press heads in the compresslon spaces, and bars for actuatingthe adpistable suspension means to close the molds and lock them inposition in the press.

6. A press comprising a stationary press 120 head, a movable press headbelow the stationary press head, interposed floating press heads adaptedto provide a plurality of compression spaces, and means arranged topermit a free upward movement of the press 125 heads for supporting thefloating press heads Y in a plurality of spaced intermediate positionsin the press when the movable press head is released. a

7. A press comprising a stationary press 130 head, a movable press headbelow the stationary press head, interposed floating press heads adaptedto provide a plurality of compression spaces, and stepped supportsadapted to hold the floating press heads in predetermined intermediatepositions in the press when the movable press head is re leased, thefloating press heads being arranged to be lifted from their supportswhen the movable press head is actuated.

8. A press comprising a stationary base, a cylinder, a plunger in thecylinder, a movable press head attached to the plunger, a stationarypress headspaced from the movable press head, an interposed floatingpress head, mold supports adjustably suspended from each of the upperpress heads, and alternate stationary racks arranged in pairs and havingguideways adapted to support molds in position to enter the moldsupports from opposite sides of the press.

9. A press comprising a stationary base, a cylinder, a plunger in thecylinder, a movable press head attached to the plunger, a stationarypress head spaced from the movable press head, an interposed floatingpress head, mold supports depending from each of the upper press heads,means for adjusting the supports to close the molds and securely holdthem against the bottoms of the press heads above, and means foractuating the movable press head to compress the material in the molds.

10. A press comprising a stationary base, a cylinder, a plunger in thecylinder, a movable press head attached to the plunger, a stationarypress head spaced from the movable press head, an interposed floatingpress head, mold supports comprising slotted bars havingupwardly-extending substantially central projections depended in pairsfrom each of the upper press heads, means for securing the projectionsof the supports to the press heads and means for elevating the supports.

11. A press comprising a stationary base, a cylinder, a plunger in thecylinder, a movable press head attached to the plunger, a

stationary press head spaced from the movable press head, an interposedfloating press head, mold supports comprising slotted bars havingupwardly-extending substantially central projections depended in pairsfrom each of the upper press heads, means for securing the projectionsof the supports to the press heads, molds adapted to be carried by theslotted supporting bars, and means for elevating the supports topreliminarily compress the material in the mold by clamping the mold tothe bottom of the adjacent head.

12. A press comprising a, stationary base, a cylinder, a plunger in thecylinder, a movable press head attached to the plunger. a stationarypress head spaced from the movhead, supporting frames secured to thebase at one end, and to the stationary press head at the other, guidebars secured to said frames and constituting a plurality of racks, moldsadapted to slide on said racks, a plurality of floating press headsinterposed between the stationary and movable press heads, and meansseverally attached to the stationary and to the floating press heads,for supporting the molds in the press.

14:. A hydraulic press comprising a base having a cylindrical recess towhich compressed fluid is supplied, a plunger operating in said recess,a movable press head secured to the plunger, a stationary press headmaterially spaced from the movable press head, supporting frames securedto the base at one end, and to the stationary press head at the other,guide bars secured to said frames and constituting a plurality of racks,molds adapted to slide on said racks, a plurality of floatin press headsinterposed between the stationary and movable press heads, and supportsseverally secured to the stationary and floating press heads and adaptedto cooperate with the guide bars of the frames to receive the moldstherefrom.

15. A hydraulic press comprising a base having a cylindrical recess towhlch compressed fluid is supplied, a plunger operating in said recess,a movable press head secured to the plunger, a stationary press headmaterially spaced from the movable press head, supporting frames securedto the base at one end, and to the stationary press head atthe other,guide bars secured to said frames and constituting a plurality of racks,molds adapted to slide on said racks, a plurality of floating pressheads interposed between the stationary and movable press heads, wedgebars adjustably attached to the stationary and floating press heads andmold supports adjustably suspended from the wedge bars and adapted tocooperate with the stationary guide bars of the frames to permit themold to be moved into and from the press, said wedge bars being arrangedto elevate the supports and clamp the molds to the bottom of the ressheads.

16. press comprising a pair of spaced press heads, means for actuatingthe press to move the heads one toward the other, an

interposed molds in the spaces between press heads, mold holders forsuspending each mold from the press head above, and transverse wedgebars for actuating the mold holders to lock the molds closed against thepress head above, independently of the press actuating means.

17. A hydraulic press comprising a base having a cylindrical recess towhich compressed fluid is supplied, a plunger operating in said recess,a movable press head secured to the plunger, a stationary press headmaterially spaced from the movable press head, supporting, framessecured to the base at one end, and to the stationary press head at theother, guide bars secured to said frames and constituting a plurality ofracks, molds adapted to slide on said racks, a plurality offloatingpress heads interbposed between the stationary and mova le pressheads, and adjustable supports depending from the stationary andfloating press heads and constituting guideways 1n alinement with thestationary guide bars of the rack.

18. A hydraulic press comprising a base having a cylindrical recess towhich compressed fluid is supplied, a plunger operating in said recess,a movable press head secured to the plunger, a stationary press headmaterially spaced from the movable press head, supporting frames securedto the base at one end, and to the stationary ress head at the other,guide bars secure to said frames and constituting a plurality of racks,molds adapted to slide on said racks, a plurality of floating pressheads interposed between the stationary and movable press heads,adjustable supports depending from the stationary and floating pressheads and constituting guideways 1n alinement with the stationary idebars of the rack, and means for supp ying heat to the press heads.

19. A hydraulic press comprisin a base having a cylindrical recess towhich compressed fluid is supplied, a plunger operating in said recess,a movable press head secured to the plunger, a stationary press headmaterially spaced from the movable press head, supporting frames securedto the base at one end, and to the stationary ress head at the other,guide bars secure to said frames and constituting a lurality of racksmolds having removable ottom plates and adapted to slide in saidguideways, supports depending from the stationary and floating pressheads, means for supporting the press heads in spaced relation and insuch position that the supports constitute guideways in alinement withthe stationary ride bars, and means for pressing upwar l on the bottomof the mold plates when t e molds are mounted in the racks.

20. A hydraulic press comprising a base 05 having a cylindrical recessto which commeanest pressed fluid is supplied, a plunger operatmg insaid recess, a movable press head secured to the plunger, a stationarypress head materially spaced from the movable press head, supportingframes secured to the base at one end, and to the stationary press headat the other, guide bars secured to said frames and constituting alurality of'racks, molds having removable ottom plates and adapted toslide in said guideways, supports depending from the stationary andfloating press heads, means, for supporting the press heads in spacedrelation and in. such position that the supports constitute guideways inalinement with the stationary guide bars, transverse bars secured to theguide bars below the mold, and elevating screws associated with thetransverse bars for forcing the bottom of the mold plate upwardly toremove the product when the mold is supported in the racks.

21. A press comprising a pair of spaced press heads, an interposed presshead, a mold adapted to be supported in each compression space of thepress and having an inwardly movable bottom adapted to coiiperate withonset the adjacent press heads, each of said press heads havingshoulders adapted to lift the mold when the bottom has been pushedinwardly to a predetermined extent.

22. A press comprising a pair of spaced press heads. an interposed presshead, a mold adapted to be supported in each compression space of thepress and having an inwardly movable bottom adapted to coiiperate withone of the adjacent press heads, a mold plate removably attached to thebottom adapted to determine the mold space.

23. A press comprising a pair of spaced press heads. an interposed presshead, a mold adapted to be supported in each compression space of thepress and having an inwardly movable bottom adapted to cooperate. withone of the adjacent heads, and a taper mold plate removably secured tothe bottom.

24. A concrete molding press comprising a pair of spaced press heads, aninterposed press head, means for supplying heat to each of the pressheads to prevent the adhesion between the concrete and the press, a moldadapted to be supported in each compression space of the press, andmeans for closing each mold before the press is actuated by clamping itto one of the heated press heads above.

25. A press comprising a pair of spaced press heads adapted to be movedone toward the other, an interposed floating press head adapted toprovide a plurality of compression spaces, mold holders for supporting amold in. each compression space, and means for actuating the holders toclamp the mold against the press head above.

26. A press comprising a pair of spaced press heads adapted to provlde acompresllllii sion space between them, means for actuating one of theheads, a mold for concrete having a movable bottom and open top adaptedto be supported in said space, means for clamping the mold to the presshead above before the press is actuated to close the top and preventloss of solid material from the mold when pressure is applied, tendingto move the heads together.

27. A press comprising a pair of spaced press heads, an interposed presshead, a mold.

adapted to be supported in each compression space in the press andhaving an inwardly movable bottom adapted to cooperate with a one of theadjacent press heads, each of said press heads having shoulders adaptedto limit the inward movement of the bottom relative to the mold.

28. A press comprising a relatively stationary horizontal press headabove, a movable press head below, means for actuating the movable presshead, a mold having an upwardly movable bottom, and means for clampingthe mold when full of plastic material against the surface of the presshead above before the press is actuated.

In Witness whereof, I have hereunto set my hand, this 31st day of May,1916.

CURT R. BURKHARDT.

